From: Jérôme BENOIS <benois@argia-engineering.fr>
To: db@zigo.dhs.org
Cc: PostgreSQL Performance <pgsql-performance@postgresql.org>
Cc: Xavier Milliard <milliard@argia.fr>
Cc: Laurent BELMONTE <belmonte@argia.fr>
Subject: Re: BitMapScan performance degradation
Date: Tue, 21 Nov 2006 16:35:56 +0100
Message-ID: <1164123356.5281.256.camel@localhost.localdomain> (raw)
In-Reply-To: <3389.192.121.104.120.1164121967.squirrel@zigo.dhs.org>
References: <1164100889.5281.184.camel@localhost.localdomain>
<3389.192.121.104.120.1164121967.squirrel@zigo.dhs.org>
Hi Dennis,
Le mardi 21 novembre 2006 à 16:12 +0100, db@zigo.dhs.org a écrit :
> > When enable_bitmapscan is enabled this query cost 51893.491 ms and when
> > is disabled 117.709 ms. But i heard bitmapscan feature improved
> > performance, can you help me ?
>
> The standard question we always ask first is if you have run VACUUM
> ANALYZE recently?
Yes i ran VACCUUM ANALYZE just before my EXPLAIN.
> Are all the costs and estimated number of rows the same after you have run
> VACUUM ANALYZE? If not you might want to show that new plan as well.
>
> /Dennis
Jérôme.
Attachments:
signature.asc (application/pgp-signature, 188B) download
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Reply to all the recipients using the --to and --cc options:
reply via email
To: pgsql-performance@postgresql.org
Cc: benois@argia-engineering.fr, db@zigo.dhs.org, milliard@argia.fr, belmonte@argia.fr
Subject: Re: BitMapScan performance degradation
In-Reply-To: <1164123356.5281.256.camel@localhost.localdomain>
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
This inbox is served by DDX for PostgreSQL; see mirroring instructions
for how to clone and mirror all data and code used for this inbox